High Speed vs lower speed cartridges.

Discussion in 'General Rifle Discussion' started by Colby, Dec 10, 2012.

  1. Colby

    Colby New Member

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    I have recently come upon some comments about the much greater destructiveness of higher speed rounds versus the lower speed sounds - against hard inanimate objects. Against flesh - well known. But against objects.
    Does anyone have any good experience with this - any guidelines as to what you should or shouldn't be shooting at - depending on how you do or don't want to tear up a certain target.
    The comments were concerning favorite set up steel plate targets that were normally used for all kinds of different cartridges - mostly pistols (but some pretty big pistols in the mix) and some rifles. The high speed high power rounds were not used against some favorite steel targets - for fear of severely damaging them - and wanting them functionable later for other demonstrations.
    Any thoughts on this.
    I'm just not that knowledgeable... But I'd like to understand.
     
  2. locutus

    locutus Well-Known Member Supporter

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    High velocity increases kinetic energy by the square of the velocity.

    For that reason, the M-1 Abrams tank uses a smooth bore main gun with a velocity of ~ 5000 FPS. The non exploding depleted uranium sabot round is the most destructive ever used by a tank.

    High explosive rounds are available for that gun, but the sabot round is the round of choice against armor.
     

  3. SSGN_Doc

    SSGN_Doc Well-Known Member

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    Alot can depend on bullet construction as well. Thin jackets and light weight bullets may not do as much damage against harder objects.

    If you are talking about shooting steel plates specifically and not wanting them torn up, then it would depend on the metal used and any hardening treatment to the metal. Most target manufacturers will rate their targets for certain types of rounds. AR 500 Brinell steel is rated against heavy rifle rounds for thousands of hits. Most handgun rated targets have half the hardness rating and can be damaged by rifle rounds.

    MGM Targets has a lot of good info on their site about steel targets, as well as a good selection of targets.
     
  4. MoreAltitude

    MoreAltitude New Member

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    I've posted this video before, but it is simply amazing. 1 million frames per second of rounds onto steel plate, plus other stuff. Hardened steel plate and softer steel targets. Doesn't really answer your question, but interesting to watch given the OP's choice of subject...


    YouTube: 1 million fps Slow Motion video of bullet impacts made by Werner Mehl

    [ame]http://youtu.be/QfDoQwIAaXg[/ame]
     
    Last edited: Dec 10, 2012
  5. oldpapps

    oldpapps New Member

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    41 years ago last summer a co-worker and I got the bright idea of making up some reusable targets out of 3/8 inch boiler plate.
    We shot these targets with a wide selection of weapons and loads.

    Soft lead splatters. Hard jacketed bullets bounce back. Very hard FMJ (military stuff) cuts a chunk of the metal out and throws is back at ya. It's very hot!
    Didn't matter if it was pistol stuff or surplus rifle stuff. Just bigger chunks.

    Going to shoot metal? Make sure the target metal is thick and at a longer distance.

    Now, I have my target stand set in front of a rock out cropping at a hundred yards. I still get some pistol round coming back from my 25 yard tree stumps.

    The upper photo is .45 ACP 230 FMJ/what was shot, into a steel tank and into a tree stump. The lower is (.40 S&W) into and back from a (new) cedar tree stump. Don't ask me to explain the 40 cal. That is lead and it came back 25 yards!

    http://www.firearmstalk.com/forums/attachment.php?attachmentid=73975&stc=1&d=1355157250

    http://www.firearmstalk.com/forums/attachment.php?attachmentid=73976&stc=1&d=1355157406
     

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  6. SSGN_Doc

    SSGN_Doc Well-Known Member

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    If using fixed steel plates it is also advised that the plates be angled leaning forward at an angle so that any spall is bounced toward the ground, and not directly back at the shooter. This also means that the area that the target is standing in should be free of rocks so that no other fragments are ricochetted back toward the shooter.
     
  7. John_Deer

    John_Deer New Member

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    Fixed plates are a bad idea for any round. I don't know the science behind it. But I have seen to many bad outcomes from people shooting fixed, immovable steel objects. If you are going to acquire silhouettes or any other steel target make sure they swing, fall or have some type of motion when a bullet strikes them. Swinging targets have given me the best results.
     
  8. HockaLouis

    HockaLouis New Member

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    Colby, energy translates into velocity, not the other way around as has been indicated above. If you put more energy into one of two otherwise identical bullets, i.e. burning more and/or faster powder behind it, it goes faster and has more energy!

    Powerful hard bullets hurt "soft" targets. Greater than 40 degrees from the perpendicular will redirect the bullet with almost all of its energy. A hard bullet can cause concavities, also known as "flats" in a plate and it is there, where a bullet hits a spot less than 40 degrees that a backwards rebounding ricochet is coming after you. Ever shoot Practical Pistol? Did they ban you from using jacketed ammo!? See...

    Look at accuracy too. .22 caliber and smaller, as a rule of thumb, tend to be more accurate the faster they go. It is the opposite for larger.
     
    Last edited: Dec 10, 2012
  9. locutus

    locutus Well-Known Member Supporter

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    The velocity of the bullet is indeed determined by the release of energy from the burning powder.

    The kinetic energy the bullet carries is a function of velocity.
     
  10. nitestalker

    nitestalker New Member

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    If you want to see amazing damage to steel targets hard or soft. Fire a .220 Swift with a 50 grs. bullet running 3,800 FPS. in to a metal plate.:eek:
     
  11. c3shooter

    c3shooter Administrator Staff Member

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    Remington Accelerator 30-06, driving a .25 caliber 55 grain bullet at 4500 fps. Acts like a hole punch. :eek:
     
  12. Jet88

    Jet88 New Member

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    My AR with 55gr Federal 5.56 @ 50 yards yesterday shooting a hinged steel target. I didn't do that again!
     

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  13. Jet88

    Jet88 New Member

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    About 3/8 inches deep into the steel
     
  14. Colby

    Colby New Member

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    A lot of good info here!

    The high velocity just simply translates into high energy, it seems. And that energy has got to be dissipated somehow. And if stopped too suddenly (steel target) - then radical stuff happens! That is pretty obvious by those videos. Those are amazing!
    The metal looks as though it goes molten briefly just at the beginning of the strike! And that is a lot of energy being converted to heat - but I guess it has to convert to molten - the stop is so abrupt!

    And this bounce back stuff is extreme!

    The comments on the small caliber being more accurate than large caliber is interesting, too. Must be that large calibers are not as aerodynamically stable - and tend to tumble a bit - in flight.
     
  15. John_Deer

    John_Deer New Member

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    In a vacuum small caliber bullets are more accurate than a large bullet. Wind gives heavier bullets an advantage in a practical environment. Most 17 HMR rifles are extremely accurate. But it's not uncommon for the wind to blow the 17 HMR two inches at 100 yards. When I shoot a 180 grain bullet from a 30/06 the wind has be howling to move the bullet in 100 yards.
     
  16. Colby

    Colby New Member

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    That puts another whole complicating aspect into the long range thing...
    Thanks!
     
  17. tuck2

    tuck2 New Member

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    You can shoot at steel plates alll you wont. The big 50 and bigger caliber muzzle loaders followed by the big bore black powder cartridges rifles killed every size of critter that is on the earth. Since smokless powder has ben used and bullet designed for much higher velocity to fit the varmint and big game we can now shoot critters at a longer rangs. A deer shot at 100 yards with a slow moving 50 caliber round ball is jest as dead as a deer shot at 100 yards with a 22-250 shooting a fast moving 60 grain bullet.
     
  18. locutus

    locutus Well-Known Member Supporter

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    That is exactly what happens.

    The depleted uranium sabot round from the 120 mm M1 Abrams main gun strikes with sufficient kinetic energy to melt armor plate and cause the sprewel to go into the tank, spraying everything inside with molten metal.
     
  19. nitestalker

    nitestalker New Member

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    A shooting accident happened today when a Military Tank was shot by a varmint hunter. The Tank was crossing a Prairie Dog town today in South Dakota when an up set hunter shot the Tank with a .220 Swift. There were no survivers.:eek:
     

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